1. Division of Non-communicable Diseases Control and Community Health; Chinese Center for Disease Control and Prevention; Beijing China
2. Department of Medicine; Duke University School of Medicine; Durham North Carolina USA
3. Department of Sociology & Anthropology; University of Rhode Island; Kingston Rhode Island USA
4. Center for the study of Aging and Human Development, School of Medicine, Duke University; Durham North Carolina USA
5. Center for Healthy Aging and Development Studies, National School of Development, Peking University; Beijing China